I am syncing project between Scrivener and Notebooks using Dropbox. All is well except that paragraph indents in Notebooks files appear as line spaces whereas files appear fine in Scrivener. Any idea why this is happening?

My guess is that you produced your paragraph indents in Scrivener by putting a tab at the beginning of each paragraph, but that Notebooks doesn’t have any tab-points set, therefore that tab is taking up a full line of however many characters and that the text is therefore beginning at the left margin of the line below.

I don’t know Notebooks, so that is only a guess.

Using an empty line (not a line space, there is no such thing) between paragraphs is a standard way of indicating paragraphs in a plain-text writing environment, otherwise you just have a big glob of text. Is that what you are referring to?